Multi-purpose adhesives and methods of making and using thereof

ABSTRACT

Described herein are adhesives that exhibit good cohesive and tack properties. In certain aspects, the adhesives can be applied to substrates using a low- or medium-pressure delivery system. The adhesives can be readily applied to any substrate such as, for example, a floor, wall, ceiling, countertop, and the like. The adhesives are particularly effective in adhering heavy materials such as, for example ceramic tiles and wall panels to walls.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. application Ser. No.12/724,015, filed on Mar. 15, 2010, which claims priority upon U.S.provisional application Ser. No. 61/160,472, filed Mar. 16, 2009. Theseapplications are hereby incorporated by reference in their entiretiesfor all of their teachings.

BACKGROUND

In general, adhesives used to secure building materials involve applyingthe adhesive to a substrate by trowel or some other spreading means.Although this may be useful in small areas, if the adhesive has to beapplied to a large area such as a floor or wall, then the application ofthe adhesive may not be straightforward and efficient. Thus, adhesivesthat can be effectively applied to substrates in an even and consistentmanner are desirable.

One approach involves the use of pressurized adhesive systems forapplying an adhesive to a substrate. Although the use of these systemsprovides an easy way to apply the adhesive over a large surface area,there are some considerations when using these systems. Traditionaladhesive systems for packaging into a pressurized container such as anaerosol can or propane type cylinder have been solvent-based compoundsbecause of good solubility, low cost, solvency in standard pressurepropellant systems such as propane, butane, and isobutene compounds andblends thereof, and in some cases high pressure propellant systems suchas nitrogen and carbon dioxide. The majority of these traditionalsystems usually contain at least some VOCs or some level offlammability. Solvent-based systems also usually carry with them anumber of undesirable health hazards, environmental concerns, or eventhe possibility of being explosive in nature. As local, state andnational governmental regulations have been tightening the requirementsfor adhesives and other chemical-based products to contain less VOC andto be more environmentally friendly, it has become necessary to researchmore environmentally friendly alternatives to adhesives.

Another issue involves the ability of the adhesive to adhere heavybuilding materials such as, for example, ceramic tiles, to walls. Theadhesive should possess good cohesion and strength, which is useful inadhering large materials to walls. However, the strength or cohesiveproperties of the adhesive has to be balanced with its tack properties.If the adhesive has very good strength characteristics but poor tackproperties, then the adhesive is not very effective. The same applies ifthe adhesive has good tack properties but poor strength.

SUMMARY

Described herein are adhesives that exhibit good cohesive and tackproperties. In certain aspects, the adhesives can be applied tosubstrates using a low- or medium-pressure delivery system. Theadhesives can be readily applied to any substrate such as, for example,a floor, wall, ceiling, countertop, and the like. The adhesives areparticularly effective in adhering heavy materials such as, for exampleceramic tiles and wall panels to walls.

The advantages of the materials, methods, and devices described hereinwill be set forth-in part in the description which follows, or may belearned by practice of the aspects described below. The advantagesdescribed below will be realized and attained by means of the elementsand combinations particularly pointed out in the appended claims. It isto be understood that both the foregoing general description and thefollowing detailed description are exemplary and explanatory only andare not restrictive.

DETAILED DESCRIPTION

Before the present materials, articles, and/or methods are disclosed anddescribed, it is to be understood that the aspects described below arenot limited to specific compounds, synthetic methods, or uses as suchmay, of course, vary. It is also to be understood that the terminologyused herein is for the purpose of describing particular aspects only andis not intended to be limiting.

In this specification and in the claims that follow, reference will bemade to a number of terms that shall be defined to have the followingmeanings:

Throughout this specification, unless the context requires otherwise,the word “comprise,” or variations such as “comprises” or “comprising,”will be understood to imply the inclusion of a stated integer or step orgroup of integers or steps but not the exclusion of any other integer orstep or group of integers or steps.

The amount of each component unless expressed otherwise is based uponthe batch adhesive composition. For example, if a polymer is from 5% to70% by weight of the composition, it is 5% to 70% by weight of theadhesive prior to the addition of other components such as, for example,a propellant.

It must be noted that, as used in the specification and the appendedclaims, the singular forms “a,” “an” and “the” include plural referentsunless the context clearly dictates otherwise. Thus, for example,reference to “a pharmaceutical carrier” includes mixtures of two or moresuch carriers, and the like.

“Optional” or “optionally” means that the subsequently described eventor circumstance can or cannot occur, and that the description includesinstances where the event or circumstance occurs and instances where itdoes not. For example, the adhesives described herein may optionallycontain one or more fillers, where the filler may or may not be present.

Described herein are adhesive compositions that can be used in a varietyof different applications. In one aspect, the adhesive compositioncomprises a mixture of:

-   -   (a) a first polymer comprising a glass transition temperature        greater than 15° C.;    -   (b) a second polymer comprising a glass transition temperature        less than 0° C.; and    -   (c) a plasticizer.        Each component of the adhesive composition as well as methods        for making and using the adhesive compositions is described        below.

The first polymer provides cohesive and strength properties to theadhesive composition. In general, the first polymer is composed of oneor more polymers having a relatively high glass transition temperature(T_(g)). Thus, the first polymer is a “hard” polymer, which requireshigher temperatures to soften the polymer relative to the secondpolymer. In certain aspects, it is desirable that the first polymerabsorb little to no water. This is particularly useful when applied tosubstrates such as, for example, drywall, where the presence of watercan generate mold and compromise the drywall.

In one aspect, the first polymer has a glass transition temperaturegreater than 15° C. In another aspect, the glass transition temperatureis from 15° C. to 25° C. or from 20° C. to 25° C. In further aspects,the glass transition temperature of the first polymer is 15° C. 16° C.17° C., 18° C. 19° C., 20° C., 21° C., 22° C., 23° C., 24° C., or 25°C., where any value can form a lower and upper end-point of atemperature range.

A variety of different polymers can be used as the first polymer. Forexample, the first polymer can be derived from monomers such as(meth)acrylic acid, C1 to C8 alkyl (meth)acrylate, C1 to C13hydroxyalkyl(meth)acrylate, di-C1 to C13 alkyl maleate/fumarate, vinylester such as vinyl acetate, styrene, butadiene, 2-chloro-1,3-butadiene,and ethylene. In one aspect, the first polymer comprises a styreneacrylic latex polymer. Examples of such polymers include, but are notlimited to, Acronal 296D (copolymer dispersion of butyl acrylate andstyrene), Acronal S 702 (acrylic-styrene copolymer anionic dispersion),and Acronal S 728 (copolymer of styrene-butyl acrylate aqueousdispersion), which are manufactured by BASF. Another example includesSaiden SA-207 (styrene acrylic) manufactured by Saiden Technologies. Inother aspects, the first polymer is a polyester polyurethane such as,for example, a carboxylated or sulfonated polyester polyurethane. Theamount of first polymer can vary depending upon the application of theadhesive as well as the selection and amounts of other components usedto make the adhesive. In one aspect, the first polymer is from 30% to90% by weight of the composition. In other aspects, the first polymer isfrom 30% to 80%, 30% to 70%, 30% to 50%, 60% to 80%, or 70% to 80% byweight of the composition.

The adhesive composition also includes a second polymer comprising aglass transition temperature less than 0° C. Due to the lower glasstransition temperature, the second polymer is “softer” than the firstpolymer. Not wishing to be bound by theory, the second polymer providesa good balance of cohesion (i.e., strength) and tackiness. It is alsodesirable that the second polymer absorb little to no water for thereasons discussed above.

In one aspect, the second polymer has a glass transition temperaturefrom −10° C. to −50° C. or from −30° C. to −40° C. In another aspect,the second polymer has a glass transition temperature less than −30° C.In further aspects, the glass transition temperature of the secondpolymer is −30° C., −31° C., −32° C., −33° C., −34° C., −35° C., −36°C., −37° C., −38° C., −39° C., −40° C., −41° C., −42° C., −43° C., −44°C., −45° C., −46° C., −47° C., −48° C., −49° C., −50° C., −51° C., −52°C., −53° C., −54° C., −55° C., −56° C., −57° C., −58° C., −59° C., −60°C., −61° C., −62° C., −63° C., −64° C., −65° C., where any value canform a lower and upper end-point of a temperature range.

In one aspect, the second polymer comprises an acrylic based polymer.Examples of second polymers useful herein include, but are not limitedto, Acronal V 275 (acrylic-vinyl acetate copolymer emulsion), Acronal3432 (a dispersion of a carboxylated acrylic polymer), Acronal 210 (anacrylate copolymer emulsion), Acronal A 200, Acronal A 280, Acronal A323, Acronal A 378, Acronal A 380, and Acronal V 312, which aremanufactured by BASF. Others include and Saiden Saitak™ 950 (acrylic)and 400™ (acrylonitrile/acrylic copolymer) manufactured by

Saiden Technologies and UCAR® latex 163S (acrylic) manufactured by UnionCarbide. The amount of second polymer can vary depending upon theapplication of the adhesive as well as the selection and amounts ofother components used to make the adhesive. In one aspect, the secondpolymer is from 5% to 70% by weight of the composition. In otheraspects, the first polymer is from 10% to 70%, 20% to 70%, 30% to 70%,or 40% to 70% by weight of the composition.

In one aspect, the second polymer can include two or more differentpolymers with varying glass transition temperatures. By selecting theappropriate second polymers, it is possible to vary the cohesive andtack properties of the adhesive composition. In one aspect, the secondpolymer includes two polymers, where the one of the polymers has a glasstransition temperature from −30° C. to −40° C. and the other polymer hasa glass transition temperature less than −40° C. or from −40° C. to −65°C. In another aspect, the second polymer includes three polymers, wheretwo of the polymers have a glass transition temperature from −30° C. to−40° C. and the third polymer has a glass transition temperature lessthan −40° C. or from −40° C. to −65° C. In another aspect, the secondpolymer can include two or more acrylic based polymers. In certainaspects, the additional second polymer can provide additional tackproperties to the adhesive composition. In one aspect, one of the secondpolymers can be a polymer or copolymer derived from alkyl acrylates suchas, for example, n-butyl acrylate or 2-ethylhexyl acrylate. Not wishingto be bound by theory, by using polymers derived from varying amounts ofan alkyl acrylate, it is possible vary the softness and, ultimately, thetack properties of the adhesive. In one aspect, the second polymerhaving a glass transition temperature less than −40° C. includes Acronal81 D (acrylic copolymer emulsion containing acrylonitrile in the polymerbackbone) manufactured by BASF and Saitack® 400 (acrylonitrile/acryliccopolymer) manufactured by Saiden technologies.

In one aspect, the second polymer can include an acrylic/vinyl acetateco-polymer (e.g., Acronal V 275) and a carboxylated acrylic polymer(e.g., Acronal 3432). In this example, the acrylic/vinyl acetateco-polymer provides more cohesion and less tack, and the carboxylatedacrylic polymer provides additional tack. In this aspect, when thesecond polymer is composed of an acrylic/vinyl acetate co-polymer andcarboxylated acrylic polymer, the acrylic/vinyl acetate co-polymer canbe present in the adhesive in an amount of 40% to 65% by weight and thecarboxylated acrylic polymer can be present in an amount from 5% to 15%by weight of the adhesive.

In certain aspects, the adhesive composition can also include one ormore plasticizers. Due to the “hardness” of the first polymer (i.e.,high glass transition temperature), a plasticizer is used to help softenthe first polymer. Thus, the plasticizer helps extend the open time ofthe adhesive (i.e., the time at which the adhesive is in the open air).In the absence of the plasticizer, the adhesive composition would hardenquickly when applied to a substrate. Thus, not only do the adhesivecompositions described herein possess good cohesive and tack properties,they also have good open times as well.

In one aspect, the plasticizer comprises a rosin ester. In certainaspects, it is desirable that the rosin ester contain minimal to noVOCs. Thus, in certain aspects, the rosin ester is used as an aqueousbased composition. Alternatively, the rosin ester can be a solvent basedcomposition (e.g., packaged in oils or organic solvents). The rosinester useful herein can be up to 50% solids, 60% solid, 70% solids, 80%solids, 90% solids, or 100% solids. Examples of suitable rosin estersinclude rosins manufactured by Arizona Chemical sold under thetradenames SYLVAGUM, SYLVALITE, SYLVAROS, or SYLVATAC. Several of theseresins are pentaerythritol modified rosin esters. In one aspect, theplasticizer is SYLVATAC® RE 5. In another aspect, the plasticizerincludes a benzoate ester. For example, the benzoate ester sold underthe tradename Benzoflex® 2088 manufactured by Genovique Specialties canbe used herein.

The amount of plasticizer can vary ranging from 0.2% to 15%, 0.2% to 5%,or 0.2% to 2% by weight of the composition. In other aspects, the amountof plasticizer is from 1% to 10%, 2% to 10%, or 5% to 10% by weight ofthe adhesive composition. In other aspects, the plasticizer can bephthalates such as alkyl benzyl phthalates; adipates including dialkyladipates; phosphates including alkyl aryl phosphates and triarylphosphates; alkyl and aryl sulfonamides; and hydrogenated terphenyls.Mixtures of two or more different plasticizers can be used herein. Forexample, SYLVATAC® RE 5 and Benzoflex® 2088 can be used together toproduce the adhesives.

In other aspects, a plasticizer is not needed. In one aspect, theadhesive composition comprises a mixture of:

-   -   (a) a third polymer comprising a glass transition temperature        −30° C. to −40° C.; and    -   (b) a fourth polymer comprising a glass transition temperature        less than −40° C.

Any of the second polymers described above can be used as the third andfourth polymer in this aspect. In one aspect, the fourth polymer has aglass transition temperature from −55° C. to −65° C., −57° C. to −63°C., −59° C. to −61° C., or about −60° C. In another aspect, the thirdpolymer includes an acrylic/vinyl acetate copolymer (e.g., Acronal®V275) and the fourth polymer includes acrylonitrile/acrylic copolymer(e.g., Saitack® 400).

In certain aspects, the adhesive compositions contain minimal to noVOCs. In one aspect, the adhesive compositions prior to combining with apropellant contain nominal to no organic solvents, where the primarysolvent is water. Thus, process oils or harmful or hazardous solventsincluding those that contain VOCs are not a necessary feature.Additional components besides the polymers and plasticizers describedabove can be used to produce the adhesives described herein. In oneaspect, the adhesive further comprises a surfactant, a stabilizer, adefoamer, a filler, a corrosion inhibitor, an antioxidant, a pHadjuster, a formaldehyde scavenger, a biocide, a fungicide, or anycombination thereof.

The surfactants useful herein can be cationic, anionic, or non-ionic. Inone aspect, the surfactant comprises a fatty acid. Examples ofsurfactants include soaps, Rohm & Haas Triton B non-ionic X-180, X-193,and X-405; Albright & Wilson Ltd. Empilan MAA fatty acid non-ionic andNP-S non-ionic; Modical® S manufactured by Henkel Corporation, which isa sulfated fatty acid that is an anionic surface-active agent. In oneaspect, the surfactant is from 0.05 to 5%, or from 0.1 to 2% by weightof the adhesive.

Suitable stabilizers include, but are not limited to, basic pHmaterials, such as caustic soda, caustic potash, ammoniated tallow,dimethyl amine, dimethyl amine, ammonia, dimethyl amino ethanol, urea,diethanolamine, triethanolamine, or morpholine. The stabilizer makes theadhesive overall more stable and ready to be mixed with the additionalconstituent components to form a stable high solids adhesive. In oneaspect, the stabilizer is caustic potash (KOH 45%) manufactured byVulcan Performance Chemicals. In one aspect, the stabilizer is from 0.1to 1.0%, from 0.1 to 0.3%, or 0.25% by weight of the adhesive. In otheraspects, freeze-thaw stabilizers can be used herein. Freeze-thawstabilizers are known in the art for preventing the freezing of theadhesives at reduced temperatures, which prevents the different polymerspresent in the adhesive from separating into different phases. In thecase when freeze-thaw stabilizers are used, they can be up to 20% byweight of the adhesive. In another aspect, the amount of freeze-thawstabilizer is from 0.5% to 20%, 0.5% to 15%, 0.5% to 10%, 1% to 10%, 2%to 10%, 3% to 10%, 4% to 10%, or 5% to 10% by weight of the adhesive.

The defoamer reduces foam formation during processing as well as foamformation that can occur once the adhesive formulation is dispensed fromthe canister. Suitable defoamers include, but are not limited to,Foamkill 600 Series, available from Crucible Chemical; Foammizer M-55,available from C. P. Hall; and Nalco 5770 and 5772, available from NalcoChemical, etc. A bactericide such as, for example, Amerstate 251,available from Drew Chemical, can be added to reduce foaming andmicrobial contamination. In one aspect, Foamaster® 111 manufactured byHenkel Corporation can be used, which is a non-silicone based defoamer.In one aspect, the defoamer is from 0.1 to 1.0%, from 0.1 to 0.5%, of0.3% by weight of the adhesive.

The filler is used as a thickener, which provides body to the adhesivecomposition. Care should be taken not to raise the viscosity to a levelthat will prevent the use of the adhesive in aerosol form or in apressurized canister dispenser. Suitable fillers include, but are notlimited to, clays. In one aspect, RC-32 clay slurry manufactured byThiele Kaolin Company can be used. In one aspect, the filler is from 1to 15%, from 5 to 10%, or from 8 to 10% by weight of the adhesive.

An antioxidant prevents corrosion of the inner surface of the mixer andcontainers holding the adhesive formulation caused by oxidation of themetal surface. Antioxidants useful herein include Wing L manufactured byPhoenix Chemical Company, Inc. Wing L is the reaction product between4-methyl-phenol, dicyclopentadiene, and isobutylene. In one aspect, theantioxidant is from 0.1 to 2%, from 0.1 to 1%, or from 0.5 to 1% byweight of the adhesive. A corrosion inhibitor in combination with theantioxidant can also be used to prevent corrosion of the inner liner ofthe mixer and other containers caused by components present in theadhesive (e.g., acrylics).

A biocide can be used to prevent the formation of microorganisms (e.g.,bacteria) that can grow over time in the adhesive composition. In oneaspect, the biocide is Rocima BT 2S biocide manufactured by Rohm andHaas, which is composed of dipropylene glycol, benzisothiazolin-3-one,water, and sodium hydroxide. In one aspect, the biocide is from 0.01 to0.3%, from 0.05 to 0.2%, or from 0.1 to 0.2% by weight of the adhesive.

In another aspect, a fungicide useful in killing mold and fungi can beincorporated into the adhesives.

A pH adjuster/formaldehyde scavenger is a complexing or sequesteringagent that reacts with aldehyde(s) present in the adhesive composition.In one aspect, the pH adjuster/formaldehyde scavenger is AMP 95®manufactured by ANGUS Chemical Company, which is composed of2-amino-2-methyl-1-propanol. In one aspect, the pH adjuster/formaldehydescavenger is from 0.1 to 2%, from 0.1 to 1%, or from 0.5 to 1% by weightof the adhesive.

In one aspect, the adhesive can include hydrocarbons (e.g., paraffin) ormineral oils. In general, the adhesives described herein have very hightack properties; however, in certain aspects, it may be desirable toreduce the tack properties and increase the releasability of theadhesive. Not wishing to be bound by theory, the hydrocarbons or oilscan accomplish this. In one aspect, the amount of hydrocarbon or oilincorporated into the adhesive is from 0.5 to 5% weight.

In one aspect, the adhesive composition comprises a first polymercomprising a styrene acrylic latex polymer (e.g., Acronal 296), thesecond polymer comprises (1) an acrylic/vinyl acetate co-polymer (e.g.,Acronal 275) and (2) a carboxylated acrylic polymer (e.g., Acronal3432), and the plasticizer comprises a rosin ester (e.g., SYLVATECRE-5). In another aspect, the adhesive composition comprises a firstpolymer comprising a styrene acrylic latex polymer (e.g., Acronal 296)in the amount from 39 to 41%, 39.5 to 40.5%, or about 40% by weight ofthe adhesive, a second polymer comprising (1) an acrylic/vinyl acetateco-polymer (e.g., Acronal 275) in the amount from 45 to 47%, 45.5 to46.5%, or about 46% by weight of the adhesive and (2) a carboxylatedacrylic polymer (e.g., Acronal 3432) in the amount from 11 to 13%, 11.5to 12.5%, or about 12% by weight of the adhesive, and a plasticizer(e.g., SYLVATEC RE-5) in the amount from 0.5 to 1.5% or about 1% byweight of the adhesive (e.g., adhesive A in Examples). In these aspects,the adhesive compositions are particularly useful for adhering ceramictiles to walls and floors.

In another aspect, the adhesive composition comprises a first polymercomprising a styrene acrylic latex polymer (e.g., Saiden-207), thesecond polymer comprises (1) an acrylic/vinyl acetate co-polymer (e.g.,Acronal 275) and (2) a carboxylated acrylic polymer (e.g., Acronal3432), and the plasticizer comprises a benzoate ester (e.g., Benzoflex®2088). In another aspect, the adhesive composition comprises a firstpolymer comprising a styrene acrylic latex polymer (e.g., Saiden-207) inthe amount from 29 to 31%, 29.5 to 30.5%, or about 30% by weight of theadhesive, a second polymer comprising (1) an acrylic/vinyl acetateco-polymer (e.g., Acronal 275) in the amount from 53 to 56%, 54% to 55%,or about 54.5% by weight of the adhesive and (2) a carboxylated acrylicpolymer (e.g., Acronal 3432) in the amount from 4 to 6%, 4.5 to 5.5%, orabout 5% by weight of the adhesive, and a plasticizer (e.g., Benzoflex®2088) in the amount from 8% to 12%, 9% to 11%, or about 10% by weight ofthe adhesive (e.g., adhesive B in Examples). In these aspects, theadhesive compositions are particularly useful for adhering sheet vinyl(e.g., heterogeneous linoleum) to walls and floors.

In the formulation above, the first polymer (Saiden-207) has a lowerviscosity compared to other first polymers such as Acronal 296. In thecase of ceramic tiles, it is desirable that the first polymer Acronal296 be thicker in order to provide more body to the adhesive. Ingeneral, ceramic tiles have grooves on the back-side. The greater bodythe adhesive has the more the grooves of the tile come into contact withthe adhesive, which enhances the performance of the adhesive. In thecase of vinyl sheets, it is desirable that the adhesive be thinner sothat a thin layer can be easily applied to the wall or floor with littleto no body.

In another aspect, the adhesive composition comprises a first polymercomprising a styrene acrylic latex polymer (e.g., Saiden-207) in theamount from 70 to 80% or 74 to 75% by weight of the adhesive, a secondpolymer comprising an acrylic (e.g., UCAR® latex 163S) in the amountfrom 5 to 15%, 10 to 15% or 11 to 12% by weight of the adhesive, and aplasticizer (e.g., SYLVATEC RE-5) in the amount from 5 to 15%, 5 to 10%,or 7 to 8% by weight of the adhesive (e.g., adhesive C in Examples). Inthese aspects, the adhesive compositions are particularly useful foradhering laminates to walls and floors.

In a further aspect, the adhesive composition comprises a third polymercomprising an acrylic/vinyl acetate copolymer (e.g., Acronal® V275) inthe amount from 40 to 60%, 45 to 55%, or about 50% by weight of theadhesive and the fourth polymer comprising an acrylonitrile/acryliccopolymer (e.g., Saitack® 400) in the amount from 40 to 60%, 45 to 55%,or about 50% by weight of the adhesive (e.g., adhesive D in Examples).In these aspects, the adhesive compositions are particularly useful foradhering panels such as, for example, fiber reinforced plastics to wallsand floors.

In another aspect, the adhesive composition comprises a first polymercomprising a styrene acrylic latex polymer (e.g., Saiden-207), thesecond polymer comprises (1) an acrylic/vinyl acetate co-polymer (e.g.,Acronal 275), (2) a carboxylated acrylic polymer (e.g., Acronal 3432),(3) an acrylonitrile/acrylic copolymer (e.g., Saitack® 400), and theplasticizer comprises a mixture of benzoate ester (e.g., Benzoflex®2088) and rosin ester (e.g., SYLVATEC RE-5).

In another aspect, the adhesive composition comprises a first polymercomprising a styrene acrylic latex polymer (e.g., Saiden-207) in theamount from 29 to 31%, 29.5 to 30.5%, or about 30% by weight of theadhesive, a second polymer comprising (1) an acrylic/vinyl acetateco-polymer (e.g., Acronal 275) in the amount from 19 to 23%, 20% to 22%,or about 21% by weight of the adhesive, (2) a carboxylated acrylicpolymer (e.g., Acronal 3432) in the amount from 14 to 18%, 15 to 17%, orabout 16% by weight of the adhesive, (3) an acrylonitrile/acryliccopolymer (e.g.,Saitack® 400) in the amount from 23 to 27%, 24 to 26%,or about 25% by weight of the adhesive and a first plasticizer (e.g.,Benzoflex® 2088) in the amount from 2% to 5%, 3% to 4%, or about 3.5% byweight of the adhesive and a second plasticizer (e.g., SYLVATEC RE-5) inthe amount from 0.1% to 2%, 0.1% to 1%, or about 0.5% by weight of theadhesive (e.g., adhesive E in Examples). In these aspects, the adhesivecompositions are particularly useful for adhering vinyl materials suchas for example VCT and LVT to walls and floors.

In another aspect, the adhesive composition comprises a first polymercomprising a styrene acrylic latex polymer (e.g., Saiden-207), thesecond polymer comprises (1) an acrylic/vinyl acetate co-polymer (e.g.,Acronal 275), (2) a carboxylated acrylic polymer (e.g., Acronal 3432),(3) an acrylonitrile/acrylic copolymer (e.g.,Saitack® 400), and theplasticizer comprises a mixture of benzoate ester (e.g., Benzoflex®2088) and rosin ester (e.g., SYLVATEC RE-5).

In another aspect, the adhesive composition comprises a first polymercomprising a styrene acrylic latex polymer (e.g., Saiden-207) in theamount from 21 to 25%, 23 to 24%, or about 23.5% by weight of theadhesive, a second polymer comprising (1) an acrylic/vinyl acetateco-polymer (e.g., Acronal 275) in the amount from 19 to 23%, 20% to 22%,or about 21% by weight of the adhesive, (2) a carboxylated acrylicpolymer (e.g., Acronal 3432) in the amount from 18 to 20%, 19 to 21%, orabout 20% by weight of the adhesive, (3) an acrylonitrile/acryliccopolymer (e.g.,Saitack® 400) in the amount from 24 to 28%, 25 to 27%,or about 26% by weight of the adhesive and a first plasticizer (e.g.,Benzoflex® 2088) in the amount from 1% to 3%, 1.5% to 2.5%, or about 2%by weight of the adhesive and a second plasticizer (e.g., SYLVATEC RE-5)in the amount from 0.1% to 2%, 0.1% to 1%, or about 0.5% by weight ofthe adhesive (e.g., adhesive F in Examples). In these aspects, theadhesive compositions are particularly useful for adhering vinylmaterials such as for example VCT and LVT to walls and floors.

In other aspects, the adhesive is composed of a single pressuresensitive adhesive having a glass transition temperature less than −20°C., or from −20° C. to −40° C., or −20° C. to −30° C. For example,acrylic emulsions such as Rhoplex™ N-619 manufactured by Rohm and Haascan be used herein. The adhesive in this aspect can contain any of theoptional components and additives described above (e.g., a biocide).

The adhesive compositions described herein can be produced without theneed of special equipment or handling. In one aspect, the methodinvolves

-   -   a. heating a plasticizer for a sufficient time and temperature        to decrease the viscosity;    -   b. admixing the plasticizer with a first polymer comprising a        glass transition temperature greater than 15° C. to produce a        first admixture; and    -   c. admixing a second polymer comprising a glass transition        temperature less than 0° C. to produce the adhesive.

Depending upon the selection and amount of plasticizer, the plasticizeris heated for a sufficient time and temperature such that theplasticizer can be poured. For example, when the plasticizer is SYLVATECRE-5, the rosin ester is heated from 80-100° F. After the plasticizerhas been heated for a sufficient time and temperature, the plasticizeris added to the first polymer to produce a first admixture. The firstpolymer and plasticizer are mixed for a sufficient time in order toproduce a homogeneous mixture. To the first admixture, optionalcomponents such as, for example, preservatives (e.g., biocides andfungicides) can be added. The second polymer(s) can then be added to thefirst admixture while stirring to produce the adhesive composition. Inthe case when two or more second polymers are used, the order can vary.The adhesive composition is for the most part a homogeneous solution.

Although the adhesives described herein can be used as is onceformulated, in certain aspects, once the adhesive composition has beenprepared, it can be admixed with one or more propellants followed by theintroduction into a pressurized delivery device. In one aspect, thepropellant is a single propellant system, which is defined herein asonly one propellant alone or with at most a nominal amount of secondpropellant (e.g., an inert gas). Thus, in this aspect, the propellantdoes not contain a significant amount of second propellant. Thepropellant can be any material typically used in aerosol applications,including fluorocarbons. In one aspect, the propellant is HFC 134A(1-1-1-2 tetrafluoroethane), which is a non-polluting and non-flammablepropellant. Additionally, HFC 134A is exempt from the list of VOC;therefore, HFC 134A is not a VOC as defined herein. In another aspectthe propellant can be an inert gas like nitrogen, argon or carbondioxide. In one aspect, the propellant can be a hydrocarbon gas, ahydrofluoroalkane or hydrofluoroalkene, or volatile organic compoundssuch as, for example, dimethyl ether.

The amount of propellant that can be used will vary depending upon thecomposition of the adhesive, the internal volume of the pressurizedcontainer, and the rate of mixing between the adhesive and propellant.In one aspect, the amount of propellant introduced into the pressurizeddelivery device produces a vapor pressure between 30 to 160 at 72° F.,between 50 to 160 at 72° F., between 60 to 120 at 72° F., between 60 to90 at 72° F., or between 65 to 80 psi at 72° F.

In another aspect, the adhesive formulation is from 10 to 90% by weightof adhesive and from 10 to 90% by weight propellant, from 60 to 90% byweight of adhesive and from 10 to 40% by weight propellant, or fromabout 80% by weight adhesive and from about 20% by weight propellant.The adhesive compositions can be packaged in an industry standardpressurized delivery device such as, for example, aerosol cans orpropane type cylinders fitted with a suitable valve system and nozzle.Depending upon the type and amount of propellant used, the propellantcan also act as a solvent, where it can dilute or thin the adhesive.

The adhesive compositions possess good release and spray properties whendispensed from the pressurized delivery device. The compositionsmaintain a relatively low internal pressure in the pressurized deliverydevice, which is desirable with respect to releasing the adhesive fromthe device in a consistent and even manner. In one aspect, spray outpressure fluctuation is between 0-60 psi at 72° F., preferably between0-10 psi at 72° F.

The adhesive compositions described herein can be sprayed in the form ofa stable foam that can be applied to a substrate at varying thicknesses(e.g., up to 0.25 inches). Upon coating a material or substrate, thefoam then returns to its original density upon the application ofpressure. The conversion of the adhesive from high density to lowdensity is achieved when the adhesive is sprayed out in a uniform manneron the surface, forming a stable bubble structure. The bubble structuremaintains and retains a low-density coating of adhesive until anothersubstrate is applied with pressure. Additionally, the bubble structureallows far greater surface coverage than traditional adhesives andexcellent, if not superior, bonding strength for many laminates such as,natural or synthetic fabric or textiles, wood, plastic, vinyls, Formica(i.e, a composite composed of a plastic laminate of paper or fabric withmelamine resin), metals, rubber, fiberglass, concrete, paper, glass,wall tile, wall panels (e.g., FRP), wall covering materials (e.g., wallpaper), and many more surfaces. Additionally, the adhesive formulationsare useful in adhering flooring materials such as, for example, carpet,sheet vinyl (e.g., linoleum), vinyl composite tiles, ceramic tiles,artificial grass, wood, marble and other such materials that exist forfloor covering and apply them to such substrates as wood, concrete andothers.

The adhesives are particularly useful in adhering heavy materials towalls such as ceramic tiles. In one aspect, the adhesives can adhere a 4in×4 in, a 6 in×6 in, a 12 in×12 in, or a 20 in×20 in tile to a wall.The combination of the increased cohesive and tack properties of theadhesives permits easy installation of large, heavy tiles to walls. Thehigh tack properties of the adhesive provide the initial quick grab ofthe tile. Thus, once the adhesive has been applied to the wall and thetile placed on the adhesive, the tile will remain on the wall withoutthe installer having to hold the tile in place. The cohesive propertiesof the adhesive provide a strong bond with the wall once the adhesivehas dried.

In other aspects, adhesives described herein are useful with homogeneouslinoleum, which are materials composed of the same vinyl material andnot layers of different materials. For example, pressure sensitiveadhesives with glass transition temperatures less than −20° C., or from−20° C. to −40° C., or −20° C. to −30° C. can be used to adherehomogeneous linoleum to a substrate. For example, acrylic emulsions suchas Rhoplex™ N-619 manufactured by Rohm and Haas can be used herein. Theadhesive in this aspect is a single polymer, and can contain any of theoptional components and additives described above (e.g., a biocide).

The adhesive compositions described herein possess additional advantagesbesides high tack and cohesive properties. The adhesives are highlywater-resistant when dry. Additionally, the adhesives resist breakdownwhen adhered to high alkaline substrates such as concrete. Yet anotheradvantage is that once the adhesive is allowed to tack and the materialthat is to be bonded is set in place with pressure, there is no slipfrom the adhered surface. In other words, the adhesives described hereinpossess high shear strength.

EXAMPLES

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how thecompounds, compositions, and methods described and claimed herein aremade and evaluated, and are intended to be purely exemplary and are notintended to limit the scope of what the inventors regard as theirinvention. Efforts have been made to ensure accuracy with respect tonumbers (e.g., amounts, temperature, etc.) but some errors anddeviations should be accounted for. Unless indicated otherwise, partsare parts by weight, temperature is in ° C. or is at ambienttemperature, and pressure is at or near atmospheric. There are numerousvariations and combinations of reaction conditions, e.g., componentconcentrations, desired solvents, solvent mixtures, temperatures,pressures and other reaction ranges and conditions that can be used tooptimize the product purity and yield obtained from the describedprocess. Only reasonable and routine experimentation will be required tooptimize such process conditions.

Preparation of Adhesives

Adhesive A

The following procedure was used to prepare adhesive A (100 lbs):

1. Acronal 296D (40 lbs) was pumped into a tank with a mixing blade, andthe mixing blade was set to high.

-   2. Sylvatec RE5 (1 lb) was heated to 80° F., then slowly added to    the tank containing Acronal 296D. The mixture was subsequently mixed    for 10 minutes.-   3. Rocima BT 2S microbicide (1 lb) was added to the tank.-   4. Acronal 3432 (12 lbs) was added to the tank, and the mixture was    mixed for 5 minutes.-   5. Acronal V-275 (40 lbs) was added to the tank, and the mixture was    mixed for 30 minutes.

Adhesive A has a pH from 5.8 to 7.4 at 70° F., a viscosity of 400 to1,000 cps at 70° F., and a solids content from 59% to 64%. In anexemplary embodiment, adhesive A (506 g) can be formulated with thepropellant HFC 134A (169 g).

Adhesive B

The following procedure was used to prepare adhesive B (100 lbs):

-   1. Saiden 207 (30 lbs) was pumped into a tank with a mixing blade.-   2. Benzoflex 2088 (10 lbs) was pumped into the tank. The mixture was    subsequently mixed for 20 minutes.-   3. Sift Rocima BT 2S microbicide (1 lb) slowly in the tank, then mix    for 15 minutes.-   4. Acronal 3432 (5 lbs) was added to the tank.-   5. Acronal V-275 (54 lbs) was added to the tank, and the mixture was    mixed for 10 minutes.

Adhesive B has a pH from 5.0 to 6.0 at 70° F., a viscosity of 600 to1,200 cps at 70° F., and a solids content from 60% to 66%. In anexemplary embodiment, adhesive B (495 g) can be formulated with thepropellant HFC 134A (165 g).

Adhesive C

The following procedure was used to prepare adhesive C (100 lbs):

-   1. Saiden 207 (74 lbs) was pumped into a tank with a mixing blade,    and the mixing blade was turned on.-   2. Benzoflex 2088 (3 lbs) was slowly pumped into the tank. The    mixture was subsequently mixed for 5 minutes.-   3. Rocima BT 2S microbicide (1 lb) was added to the tank.-   4. Carbamide (urea) (3 lb) was added to the tank.-   5. Ucar Latex 163 S (3 lb) was added to the tank.-   6. Sylvatec RE5 (7 lb) was added to the tank.-   7. The mixture was mixed for 10 minutes.

Adhesive C has a pH from 7.5 to 8.5 at 70° F., a viscosity of 600 to1,200 cps at 70° F., and a solids content from 60% to 66%. In anexemplary embodiment, adhesive C (468 g) can be formulated with thepropellant HFC 134A (156 g).

Adhesive D

The following procedure was used to prepare adhesive D (100 lbs):

-   1. Saitack® 400 (49.9 lbs) was pumped into a tank with a mixing    blade, and the mixing blade was turned on.-   2. Acronal V-275 (49.6 lbs) was added to the tank, and the mixture    was mixed for 10 minutes.-   3. Rocima BT 2S microbicide (0.5 lb) was added to the tank, and the    mixture was mixed for 10 minutes.

Adhesive D has a pH from 4.2 to 5.0 at 70° F., a viscosity of 300 to 800cps at 70° F., and a solids content from 61% to 66%. In an exemplaryembodiment, adhesive C (510 g) can be formulated with the propellant HFC134A (145 g).

Using similar procedures described above, adhesives D and E wereprepared as well (all amounts in weight %).

Adhesive E SA 207 30 S400 25.3 Benzoflex 2088 3.5 Sylvatac RE5 0.5Acronal V-275 21 Rocima BT 2S Microbicide 0.8 Urea 2.5 Disperbyk 187 0.4Acronal 3432 16

Adhesive F SA 207 23.60 S400 26.25 Benzoflex 2088 2.20 Sylvatac RE5 0.56Acronal V-275 21.13 Rocima BT 2S Microbicide 0.9 Urea 1.80 Disperbyk 1870.46 Acronal 3432 20 VPCL-609 3.11Performance Testing

The ANSI A136.1 test was used to evaluate the performance of adhesive A.Adhesive A was sprayed on the back of 4¼×4¼ wall tile. The adhesive wassprayed until there was consistent coverage and then allowed to becometacky for 10 minutes. After 10 minutes a second wall tile was applied tothe first tile, leaving a ¼ inch offset. Pressure was applied by handbefore a 15 lb weight was set on top. The weight remained on the surfacefor 3 minutes. There were no spacers used. The bond assemblies werecured as listed below. Table 1 summarizes the test results.

TABLE 1 TEST/DESIGNATION EVALUATION ANSI SPECIFICATION Shear Strength,82 psi 50 PSI  7-Day Shear Strength Wet,  6 psi 50 PSI Type I ShearStrength Wet,  9 psi 20 PSI Type II Shear Strength 70 psi 50 PSI 28 DaysAccelerated Aging 81 psi Not less than 75% of 7-day shear value HeatResistance Maintained load for “Tile assembly shall 24 hrs maintain a 10lb. static load in shear without failure for 24 hrs. 9 Impact Test Alltiles remained “All tiles must remain bonded. bonded after impact” StainTest 0% penetration “Staining shall not exceed 70% penetration” Test forMold Growth Did not support mold “Adhesive shall not mold growth growth”

As summarized in Table 1, adhesive A exhibited many desirable propertiessuch as high shear strength, heat resistance, stain resistance, and moldresistance. These features are particularly desirable when using theadhesive in numerous flooring applications where the flooring andadhesive can be exposed to harsh conditions on a continuous basis.

Throughout this application, various publications are referenced. Thedisclosures of these publications in their entireties are herebyincorporated by reference into this application in order to more fullydescribe the compounds, compositions and methods described herein.

Various modifications and variations can be made to the materials,methods, and articles described herein. Other aspects of the materials,methods, and articles described herein will be apparent fromconsideration of the specification and practice of the materials,methods, and articles disclosed herein. It is intended that thespecification and examples be considered as exemplary.

The invention claimed is:
 1. A method for adhering a flooring materialto a floor comprising (a) spraying an adhesive consisting of a mixtureof (i) an emulsion of water and a copolymer consisting of butyl acrylateand isobutyl acrylate having a glass transition temperature from −20° C.to −30° C., a dynamic viscosity of 350 mPa·s to 800 mPa·s, a solidscontent of 56% by weight to 58% by weight, and optionally a stabilizer,a defoamer, a filler, a biocide, a fungicide, a preservative, ahydrocarbon, mineral oil, or any combination thereof, wherein theemulsion is from 45% to 85% by weight of the aqueous-based adhesive, and(ii) a propellant to the substrate to produce a coated floor, and (b)applying the flooring material to the coated floor.
 2. The method ofclaim 1, wherein the flooring material comprises carpet, carpet padding,athletic surfaces, vinyl composite tile (VCT), vinyl tile, resilientsheet goods, ceramic tile, wood flooring, synthetic flooring material,cove base, a laminate, sheet vinyl, or floor covering padding.
 3. Themethod of claim 1, wherein the floor comprises Styrofoam, textilefabrics, natural and synthetic fibers, Formica, wood, metals,fiberglass, concrete, sheet rock, masonry materials, plastic, vinyl,glass, leather, or rubber.
 4. The method of claim 1, wherein theflooring material is sheet vinyl.
 5. The method of claim 4, wherein thesheet vinyl is linoleum.
 6. The method of claim 1, wherein thepropellant is from 10% to 90% by weight of the adhesive.
 7. The methodof claim 1, wherein the propellant is from 10% to 20% by weight of theadhesive.